Intelligence Assessment

On the dawn of the second century of scientific-based mental testing, the intelligence is viewed as a diffuse notion with a great number of theories, attempting to explain it. There's no universal definition of what intelligence is and that's why each of them tend to explain it in its own way. A commonly accepted definition is by Boring (1923), stating that "intelligence is what is measured by intelligence tests", or I would say, it is what they try to measure. What is important for this essay is that the subject measured by intelligence tests is a variety of cognitive abilities (semantic relations, general reasoning, sensorimotor functioning, spatial orientation, etc), with the values behind the intelligence term tending to express the overall score.

The first widely accepted scientific intelligence assessment method was developed by Alfred Binet (Figure 6) in 1905 in cooperation with Theodore Simon. Designed to identify the subnormal children, who could potentially experience troubles...

There's a belief, that most fundamental principles in psychometrics and testing became available by 1930, and that with a few exceptions, the remainder of the 20th century was devoted to applying or refining these principles.